1. Field of the Invention
The present invention is in the field of accumulator devices and is directed more particularly to a hydraulic accumulator device of the type used for pulsation dampening and energy storage in hydraulic systems and the like.
2. The Prior Art
The use of accumulators for energy storage and pulsation dampening is today common place. A multiplicity of forms of hydraulic accumulators have heretofore been employed to satisfy the numerous industrial requirements therefor.
Typically, a hydraulic accumulator device includes a shell or pressure vessel having an oil port at one end and a gas charging port at the other. The oil port is provided with a nipple fixture or like connector enabling the same to be connected to the oil line of a hydraulic system. A bladder of elastomeric material is mounted within the pressure vessel and divides the vessel into two discrete chambers namely a chamber connected with the oil port and a chamber in communication with the gas charging port.
Examples of known fluid pressure accumulators may be found in U.S. Pat. Nos. 3,195,577 of July 20, 1965, 3,211,348 of Oct. 12, 1965 and 3,256,911 of June 21, 1966.
While the accumulator devices of the prior art as represented by the above noted patents provide effective energy storage and dampening structures, the costliness of such structures have prevented their wide spread use in mass produced environments, such as automobiles, wherein large competitive advantages are derived from even small cost reductions. More particularly, the pressure vessel components of the prior art devices, which form a principal element of the cost of the devices and which heretofore have been formed by forging, casting or spinning operations, have mandated a high initial cost factor for the accumulator. A further cost increasing factor has been the complexity of the accumulators of the prior art and the complex methods required for their assembly. More particularly, it is frequently necessary to utilize welding steps both to mount internal components within the accumulator and to complete the formation of the pressure vessel per se which is often fabricated of separate halves which must be connected.